--- product_id: 75938952 title: "Opus BT - C3100 V2.2 Universal Battery Charger Speedy LCD Display Smart Battery Charger for Rechargeable Batteries Ni-MH Ni-Cd AA AAA,3.7V Li-ion 18650 26650 17670 14500 18490 (4-Slot)" brand: "opus" price: "459.36 DT" currency: TND in_stock: true reviews_count: 5 category: "Opus" url: https://www.desertcart.tn/products/75938952-opus-bt-c3100-v2-2-universal-battery-charger-speedy-lcd store_origin: TN region: Tunisia --- # 4 independent charging slots Speedy LCD with real-time voltage & capacity Advanced thermal shutdown & cooling fan Opus BT - C3100 V2.2 Universal Battery Charger Speedy LCD Display Smart Battery Charger for Rechargeable Batteries Ni-MH Ni-Cd AA AAA,3.7V Li-ion 18650 26650 17670 14500 18490 (4-Slot) **Brand:** opus **Price:** 459.36 DT **Availability:** βœ… In Stock ## Summary > πŸ”‹ Power Up Like a Pro β€” Charge Smarter, Not Harder! ## Quick Answers - **What is this?** Opus BT - C3100 V2.2 Universal Battery Charger Speedy LCD Display Smart Battery Charger for Rechargeable Batteries Ni-MH Ni-Cd AA AAA,3.7V Li-ion 18650 26650 17670 14500 18490 (4-Slot) by opus - **How much does it cost?** 459.36 DT with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.tn](https://www.desertcart.tn/products/75938952-opus-bt-c3100-v2-2-universal-battery-charger-speedy-lcd) ## Best For - opus enthusiasts ## Why This Product - Trusted opus brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Smart LCD Display:** Track voltage, current, capacity, and charging time at a glance with backlit clarity. - β€’ **Advanced Safety Features:** Overheat detection, overcharge, short-circuit, and over-discharge protections keep your batteries and charger safe. - β€’ **Customizable Charging Currents:** Select from 200mA up to 2000mA for precise, battery-safe charging tailored to your needs. - β€’ **Versatile Multi-Mode Operation:** Charge, discharge, refresh, test, and quick test modes empower you to maintain battery health like a pro. - β€’ **Charge 4 Batteries Simultaneously:** Maximize efficiency with 4 independent slots supporting AA, AAA, and multiple Li-ion sizes. ## Overview The Opus BT-C3100 V2.2 is a universal 4-slot smart battery charger designed for Ni-MH, Ni-Cd, and various Li-ion rechargeable batteries including popular sizes like 18650 and 26650. Featuring a fast, backlit LCD display, customizable charging currents up to 2000mA, and multiple modes (charge, discharge, test, refresh), it ensures precise battery maintenance. Enhanced safety with thermal shutdown and overcharge protection makes it ideal for professionals managing multiple battery types simultaneously. ## Description Main Features: The charger integrates the minus delta voltage for NiCd or NiMh battery charging termination, and for Li-ion batteries charging to 4.2V with pre-selected constant current. ( 3.7 Li-FeO4 and 4.35 type high voltage batteries charging mode can be selected through switch on board ) Easy to read LCD with back light Showing Battery Voltage, Charge / Discharge Current, Charging Time, Battery Capacity etc. Operating temperature: 0 - 40 deg.C Max charging capacity: Up to 20000mAh Power adapter: DC 12V, 3.0A ( Output ), 100 - 240V, 50 / 60Hz ( Input ) Highlight: 1. Voltage update rate is 30s instead of 60s. 2. 4.35V charging time can be very long because charging current is regulated in entering the CV stage at 4.12V, which is same as 4.2V type. Now 3.35V charging algorithm is changed to 4.27V. 4. New fan cover make better protection for cooling fan. 5. Charging current range ( mA ): 200, 300, 500, 700, 1000, 1500, 2000 6. Discharge current range ( mA ):200, 300, 500, 700, 1000 ( li-ion cell battery only ) 7. Max. charging capacity: 20000mAh 8. Voltage deviation: max 0.03V 4.2V 9. Current deviation: max 5% Type: Charger Brand: Opus Model: BT-C3100 V2.2 Rechargeable Battery Qty: 4 Input Voltage: AC 100~240V 50/60HZ Output Voltage: DC 12V, 3.0A LCD Screen: YES Auto Circuit Detection: YES Built-in Protected Circuit: YES Over Voltage Protection: YES Short-Circuit Protection: YES Over-Charging Protection: YES Over-Discharging Protection: YES Battery Quantity: 4 Package weight: 0.558 kg Product size (L x W x H): 14.4 x 9.8 x 3.9 cm / 5.66 x 3.85 x 1.53 inches Package size (L x W x H): 16 x 22 x 5 cm / 6.29 x 8.65 x 1.97 inches Package Contents: 1 x Opus BT - C3100 Battery Charger 1 x US Power Adapter 1 x English User Manual Review: Fantastic Charger - Mostly charging 18650's and 26650's, but this is the best charger I've used so far. Started with an old Nitecore 2bay, then to a LUC2, up to a LUC 4, and next to a XTAR VC4. The LUC4 and VC4 ended up having issues with the voltage output, which is why they were replaced. I still have a VC2 charger for travel and have no issues with that one after about 2 years, but that's for when i'm on the road. First off, this comes with everything, which is sadly not the case with other chargers, but here you don't have to worry about buying an extra power supply like with the VC4. Second, the fan (in v2.2) is awesome. Unlike my other chargers, I've yet to remove a battery that is hot after charging. I always let the batteries rest before use, but I still like that they aren't hot after charging. The fan can be loud, or just high pitched, so I wouldn't want this thing in my bedroom...on in the master bath, but anywhere else is fine as it's almost always easily tuned out (its running right now in my home office and I can only hear it after mentioning this). Third, the charge is accurate with a wide range of options and voltages to choose from. I've already tested and fixed one battery, but other than that I usually just charge at 500ma, which it had no problems doing in all four slots. I even went up to 1kma and it had no problems in all 4 slots. I replaced the LUC4 and VC4 because after a year, the charging became inconsistent even with new batteries; time will tell if this charger will do the same but it's working better than the others so far. The display takes a little getting used to and selecting different charges for different bays can be a little wonky, but it's easy to figure out and get used to. Over all I'm very happy with the charger and would recommend it over XTAR, Efest, and Nitecore's chargers. Review: Outstanding Battery Tester/Charger - Out of the Box: The unit came with the base station, and power supply and Manual. Pros: I found these to be very well design elements of this unit both before, during and after using it: Modes: There are 5 different modes that can be selected for the unit to perform. Charging, Discharging, Refresh, Test, and Quick Test. Having this many options for your batteries is quite nice! Overheating protection: It has a temperature control monitor and a cooling fan built into the system and it does a very nice job. But that doesn't mean you shouldn't monitor the batteries. When you get a "heater" on you hands, the unit will keep dumping more and more power into that bad battery and struggle to keep the unit cool. I have a laser temperature unit to keep track of the batteries. Display: I found this very useful. you can cycle through all the settings the unit is currently set for without disrupting the process, including the current status of the process that it is doing. Current: This is my favorite part of the unit. You can charge or discharge 4 cells at the same time at 1000mAh or 1 amp for Lithium Ion cells. you are also given charging options of 200, 300, 500, 700, 1000, 1500 and 2000mAh. However for the upper charging mAh options you have to use certain slots and only 2 can be done at the same time. Voltage meter: Now I only use the voltage from my multimeter as the actual voltage of a cell. But this unit isn't dumb. If it reads that the voltage of a cell is low, it will not simple start dumping the selected mAh current you selected into the cell. It automatically drops the current down to a very small "trickle" charge until the voltage comes up enough to start putting in the selected current. I like this feature! Backlit Display: You have the option of having the backlit display on all the time or having it turn itself off after a preprogrammed amount of time. Multiple Cell options: Way too many to list here, but trust me this baby can handle all kinds of batteries. Cons: Resetting: I've not figured out what the conditions are that cause this unit to reset during the charging process. It's not over heating, or power drops or the power supply, but for some reason the unit will auto reset to the default charge settings which are 500mAh. the only thing I have figured out that overrides this is to select all the bays and cycles through the modes back to charge and setting the current back to 1000mAh. Very frustrating indeed considering how much I like this unit. Fans: While I did list this as a big Pro, it is also a Con in the fact that there is a balancing problem with how these units are manufactured. The fans will try to spin up and make a hell of a noise because they are out of balance or something. This happens multiple times until finally they start to spin up without issue. I've learned to live with it, but it is something to consider if you are planning on buying this unit. Wish List: More powerful power supply unit. The PSU that comes with the device does a good job, but it is only rated at 12DC and input of 100-240V at 50/60Hz and the output is 12v DC at 3.0A, which seems odd that it can charge at 4A. So IMO a more powerful PSU is needed. Personal experience: I'm building a DIY powerwall for my house, and I have 1000's of 18650 cells to process. I have 5 of these units working around the clock and other than the Con I listed regarding resetting (which only happens on the oldest unit) these babies do a great job! Bottom Line: Overall this product works as advertised, and performs perfectly on both large and small jobs. Recommendation: Damn Good Buy! ## Features - Plug: US adapter,Charging Cell Type: Ni-MH, NiCd, Lithium Ion,Designed for AA ( LR6 ) and AAA ( LR3 NiCd, NiMH or 3.7V Li-ion rechargeable batteries in size type of 10440, 14500, 16340, 17335, 17500, 18490, 17670, 18650 - Note: Battery not included,The charging current can be selected to be 200mA, 300mA, 500mA, 700mA or 1000mA (1500mA and 2000mA can only be applied when only slot 1 or 4 is selected). Default discharging current is 500mA - It provides four independent charging slots for rechargeable batteries. The charger can charge batteries of different types and sizes and with different capacities at the same time - Four Working Mode Available at User's Choice: Charge, Discharge, Test, Quick Test and Refresh,The charger also includes overheat detection to protect rechargeable batteries and charger itself from overheating - Better safety feature: PCB temperature was used to in controlling fan on / off only with 2.0V, now this function is enhanced so that temperature is monitored for entering thermal shutdown mode when excessive high temperature is reached. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B01852TBOU | | Customer Reviews | 4.5 4.5 out of 5 stars (803) | | Date First Available | November 18, 2015 | | Is Discontinued By Manufacturer | No | | Item Weight | 8.3 ounces | | Item model number | US126488801M | | Manufacturer | GBlife | | Product Dimensions | 5.67 x 1.54 x 3.86 inches | ## Product Details - **Brand:** OPUS - **Color:** purple - **Item Weight:** 8.32 ounces - **Output Voltage:** 12 Volts - **Product Dimensions:** 1.54"D x 3.86"W x 5.67"H ## Images ![Opus BT - C3100 V2.2 Universal Battery Charger Speedy LCD Display Smart Battery Charger for Rechargeable Batteries Ni-MH Ni-Cd AA AAA,3.7V Li-ion 18650 26650 17670 14500 18490 (4-Slot) - Image 1](https://m.media-amazon.com/images/I/513A3qFOAcL.jpg) ## Questions & Answers **Q: What is the difference between the c3100 and the c3400? is it just the car charger comes with the c3400? tyia** A: Some people responding to this question need to read more carefully. The question was about the difference between the C3100 and C3400 (NOT the C2400). The BT-C3400 can be bought with or without the car charger. Obviously, the one without the car charger is cheaper (but not offered on Amazon at this moment). Typically the BT-C3400 without the car charger is still a few dollars more expensive than the BT-C3100. As far as the charger itself, both models are *almost* identical, but supposedly intended for different markets. The BT-C3100 with the most recent firmware has a Lithium discharge cutoff voltage of 2.8 volts. The BT-C3400 has a discharge cutoff of 3.1 volts. Opus claims the change was made to be more in align with international standards. Some people also think that the 3.1 volt discharge cutoff is better for the batteries, but LiIon batteries should never be stored long term at either of these voltages. Be aware that both models have a hidden voltage selector switch under the back cover than will allow you to do a storage charge of 3.7 volts on standard LiIons. There is also a 4.35v charge mode setting that allows charging LiHV cells. **Q: Can this charger be used with Netgear Arlo rechargeable batteries at 2300 mah wen 2000 mah looks like max output from charger?** A: The maximum battery capacity this charger can handle is 20,000mAh. This should not be confused with the maximum charging current of 2000mA.Note that Capacity (mAh) = Current (mA) * Time (h). That means to recharge a 20,000mAh battery at 2000mA will take ~10 hours. **Q: Does this have the ability to test batteries strength? not just good/bad but how many volts and amps it will put out** A: It has quick test which I believe is the battery impedance. Multiply the battery impedance times the current draw of your application. The result is the voltage drop internal to the battery. If that number is significant, like more than about a few % of the battery voltage the loss will heat up the battery. The most discharge current is 2000 mA or 2 Amperes. **Q: Which version currently ships? v3.1, as in bt-c3400?** A: The one I got has this on the label : Under the upc barcode: X0014AV9TH Part number : Opus BT - C3100 V2.2 Dig... - US Plug (Purplish Blue) The case, the plug and the cable are all black. The only thing I can see that would relate to the purplish blue reference is the color of the LCD screen once it is plugged in to the power outlet. Otherwise the entire physical charger cable and plug are all black. It works great for me. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Fantastic Charger *by I***N on November 12, 2016* Mostly charging 18650's and 26650's, but this is the best charger I've used so far. Started with an old Nitecore 2bay, then to a LUC2, up to a LUC 4, and next to a XTAR VC4. The LUC4 and VC4 ended up having issues with the voltage output, which is why they were replaced. I still have a VC2 charger for travel and have no issues with that one after about 2 years, but that's for when i'm on the road. First off, this comes with everything, which is sadly not the case with other chargers, but here you don't have to worry about buying an extra power supply like with the VC4. Second, the fan (in v2.2) is awesome. Unlike my other chargers, I've yet to remove a battery that is hot after charging. I always let the batteries rest before use, but I still like that they aren't hot after charging. The fan can be loud, or just high pitched, so I wouldn't want this thing in my bedroom...on in the master bath, but anywhere else is fine as it's almost always easily tuned out (its running right now in my home office and I can only hear it after mentioning this). Third, the charge is accurate with a wide range of options and voltages to choose from. I've already tested and fixed one battery, but other than that I usually just charge at 500ma, which it had no problems doing in all four slots. I even went up to 1kma and it had no problems in all 4 slots. I replaced the LUC4 and VC4 because after a year, the charging became inconsistent even with new batteries; time will tell if this charger will do the same but it's working better than the others so far. The display takes a little getting used to and selecting different charges for different bays can be a little wonky, but it's easy to figure out and get used to. Over all I'm very happy with the charger and would recommend it over XTAR, Efest, and Nitecore's chargers. ### ⭐⭐⭐⭐⭐ Outstanding Battery Tester/Charger *by T***S on May 17, 2017* Out of the Box: The unit came with the base station, and power supply and Manual. Pros: I found these to be very well design elements of this unit both before, during and after using it: Modes: There are 5 different modes that can be selected for the unit to perform. Charging, Discharging, Refresh, Test, and Quick Test. Having this many options for your batteries is quite nice! Overheating protection: It has a temperature control monitor and a cooling fan built into the system and it does a very nice job. But that doesn't mean you shouldn't monitor the batteries. When you get a "heater" on you hands, the unit will keep dumping more and more power into that bad battery and struggle to keep the unit cool. I have a laser temperature unit to keep track of the batteries. Display: I found this very useful. you can cycle through all the settings the unit is currently set for without disrupting the process, including the current status of the process that it is doing. Current: This is my favorite part of the unit. You can charge or discharge 4 cells at the same time at 1000mAh or 1 amp for Lithium Ion cells. you are also given charging options of 200, 300, 500, 700, 1000, 1500 and 2000mAh. However for the upper charging mAh options you have to use certain slots and only 2 can be done at the same time. Voltage meter: Now I only use the voltage from my multimeter as the actual voltage of a cell. But this unit isn't dumb. If it reads that the voltage of a cell is low, it will not simple start dumping the selected mAh current you selected into the cell. It automatically drops the current down to a very small "trickle" charge until the voltage comes up enough to start putting in the selected current. I like this feature! Backlit Display: You have the option of having the backlit display on all the time or having it turn itself off after a preprogrammed amount of time. Multiple Cell options: Way too many to list here, but trust me this baby can handle all kinds of batteries. Cons: Resetting: I've not figured out what the conditions are that cause this unit to reset during the charging process. It's not over heating, or power drops or the power supply, but for some reason the unit will auto reset to the default charge settings which are 500mAh. the only thing I have figured out that overrides this is to select all the bays and cycles through the modes back to charge and setting the current back to 1000mAh. Very frustrating indeed considering how much I like this unit. Fans: While I did list this as a big Pro, it is also a Con in the fact that there is a balancing problem with how these units are manufactured. The fans will try to spin up and make a hell of a noise because they are out of balance or something. This happens multiple times until finally they start to spin up without issue. I've learned to live with it, but it is something to consider if you are planning on buying this unit. Wish List: More powerful power supply unit. The PSU that comes with the device does a good job, but it is only rated at 12DC and input of 100-240V at 50/60Hz and the output is 12v DC at 3.0A, which seems odd that it can charge at 4A. So IMO a more powerful PSU is needed. Personal experience: I'm building a DIY powerwall for my house, and I have 1000's of 18650 cells to process. I have 5 of these units working around the clock and other than the Con I listed regarding resetting (which only happens on the oldest unit) these babies do a great job! Bottom Line: Overall this product works as advertised, and performs perfectly on both large and small jobs. Recommendation: Damn Good Buy! ### ⭐⭐⭐⭐⭐ Review *by B***S on February 4, 2019* This is a great little 4 cell charger, charges cells 4.17 volts which I have confirmed with my Fluke multimeter to be correct. Does a quick internal check for resistance and a comprehensive refresh cycle, which takes forever if have to many cells. Don’t hesitate this and the Lakota are the best. ## Frequently Bought Together - Opus BT - C3100 V2.2 Universal Battery Charger Speedy LCD Display Smart Battery Charger for Rechargeable Batteries Ni-MH Ni-Cd AA AAA,3.7V Li-ion 18650 26650 17670 14500 18490 (4-Slot) - Eneloop Panasonic BK-4MCCA10FA AAA 2100 Cycle Ni-MH Pre-Charged Rechargeable Batteries, 10-Battery Pack - Eneloop Panasonic BK-3MCCA16FA AA 2100 Cycle Ni-MH Pre-Charged Rechargeable Batteries, 16-Battery Pack --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.tn/products/75938952-opus-bt-c3100-v2-2-universal-battery-charger-speedy-lcd](https://www.desertcart.tn/products/75938952-opus-bt-c3100-v2-2-universal-battery-charger-speedy-lcd) --- *Product available on Desertcart Tunisia* *Store origin: TN* *Last updated: 2026-06-13*